Table 2 The Results on baseline and slope for Fitting Different Individual Growth Models in Disability Trajectory Outcome Oswestry Disability Index within 1-year follow-up

ODI at BL

22

20, 23

< 0.001

12

9.9, 15

< 0.001

12

9.4, 15

< 0.001

SBST category

 Low

—

—

—

—

 Medium^e

12

8.9, 15

< 0.001

11

7.8, 14

< 0.001

 High

23

18, 27

< 0.001

22

17, 27

< 0.001

Type leg pain

 LBP

—

—

—

—

 Referred^f

2.7

-0.13, 5.6

0.061

2.5

-0.64, 5.7

0.12

 Radicular

12

6.4, 18

< 0.001

15

9.0, 22

< 0.001

linear change during first 6 months

-6.3

-7.1, -5.6

< 0.001

-3.6

-5.0, -2.2

< 0.001

-2.2

-3.7, -0.67

0.005

SBST category * linear change during first 6 months

 Medium * linear change during first 6 months

-5.0

-6.6, -3.3

< 0.001

-6.2

-8.0, -4.4

< 0.001

 High * linear change during first 6 months

-7.0

-9.7, -4.3

< 0.001

-9.2

-12, -6.3

< 0.001

Type leg pain * linear change during first 6 months

 Referred * linear change during first 6 months

-0.05

-1.7, 1.6

> 0.9

-0.34

-2.1, 1.4

0.7

 Radicular * linear change during first 6 months

0.03

-3.3, 3.4

> 0.9

-1.3

-4.9, 2.3

0.5

quadratic change during first 6 months

0.72

0.60, 0.83

< 0.001

0.41

0.20, 0.62

< 0.001

0.23

0.00, 0.45

0.053

SBST category * quadratic change during first 6 months

 Medium * quadratic change during first 6 months

0.64

0.39, 0.89

< 0.001

0.80

0.52, 1.1

< 0.001

 High * quadratic change during first 6 months

0.75

0.34, 1.2

< 0.001

1.1

0.62, 1.5

< 0.001

Type leg pain * quadratic change during first 6 months

 Referred * quadratic change during first 6 months

-0.02

-0.27, 0.23

0.9

0.01

-0.26, 0.28

> 0.9

 Radicular * quadratic change during first 6 months

-0.16

-0.67, 0.35

0.5

-0.04

-0.59, 0.51

0.9

difference between ODI at 6 and 12 months

-1.5

-2.9, -0.22

0.023

-1.9

-4.2, 0.44

0.11

-2.5

-5.1, 0.08

0.058

SBST category * difference between ODI at 6 and 12 months

 Medium * difference between ODI at 6 and 12 months

0.38

-2.5, 3.2

0.8

1.1

-2.1, 4.3

0.5

 High * difference between ODI at 6 and 12 months

3.8

-0.93, 8.5

0.12

5.7

0.64, 11

0.027

Type leg pain * difference between ODI at 6 and 12 months

 Referred * difference between ODI at 6 and 12 months

-0.18

-3.0, 2.6

0.9

0.03

-3.0, 3.1

> 0.9

 Radicular * difference between ODI at 6 and 12 months

-1.5

-7.6, 4.7

0.6

-1.9

-8.6, 4.7

0.6

random intercept (sd)

12

9.5

9.4

correlation random effects

-0.72

-0.64

-0.67

random linear slope (sd)

1.5

1.4

1.4

residuals (sd)

8.7

8.6

8.4

AIC

12,82

12,47

10,39

BIC

12,86

12,60

10,64